 Piezoelectric biosensors are analytical devices that measure changes in electrical properties when they come into contact with biological materials such as proteins, DNA, and other substances. These sensors can be used for a variety of purposes including drug detection, disease diagnosis, and environmental monitoring. They work by detecting changes in the electrical properties of a piezoelectric material when it comes into contact with a specific target. This can be done through either an affinity interaction or a change in the frequency of vibration. This article was authored by Miroslav Pohanka.